Handcrafted tumbled marble coasters by Studio Vertu. Each set/4 of coasters is handcrafted by our trained artisans in the USA. Because we use natural stone, variations are to be expected, and enhance the unique beauty of each tile! To clean, use a damp cloth and wipe clean. Do not use any harsh chemicals or abrasives. Dimensions: 4x4 tumbled Botticino marble. Corked backed 3 lbs